Hydraulic coupling



Sept. 1, 1942. w. BLACK erm. l HYDRAULIC 'coUPLIN'G 2 Sheets-Sheet 1 Filed May 3, 1939 Illlllll Sept.1,1942. w. am.; m.. 2,294,768

HYDRAULIC COUPLING f Filed May :5, 1953 2 sheets-sheet 2 Iventors: y wing BlacKf, 1 Rudol` Fichtner",

I bg C Their- Attorney. -Y

I Patented sept. 1, 1942 HYDRAUHC CoUrLlNG Willy Black, Berlin-Halensee, and Rudolf Fichtner, Berlin, Germany, assignors to General Electric Company,` a corporation of New York Application May 3, 1939, Serial No. 271,554

In Germany May 11, 1938 4 oieims. (ci. so-s4) Our invention relates to hydraulic couplings, and more particularly to the Fttinger type of couplings which are sometimes referred to as hydro-kinetic couplings.

One object of our invention is to provide an improved structure wherein elements of the coupling having dierent temperature coeilicients of expansion may operate in relation toeach other throughout the full range of operating temperatures without creating undue strains within the coupling.

. For a better understanding of our invention,

together with other and further objects thereof, reference is had to the following description taken in connection with thev accompanying drawings, and its scope will be pointed Vout in the appended claims.

y cation of Fig.l 2.

In a coupling of the `-type above-mentioned,

the casing is made of cast iron, or of steel, which has a relatively low temperature coefficient of expansion, and the diaphragms within this casing are made of light weight metal such as aluminum, or aluminum alloys, for example, which have a relatively high temperature coefl'icient of expansion. The temperature range between summer full load operating ltemperatures and winter starting temperatures is approximately between 100 C. and 20 C. Over this range ofA 120, the diameter of a 400 mm. steel casingmay vary as much as .53 mm. and the diaphragm of aluminum or an alloy thereof will expand as much as twice that amount. The difference in the above-mentioned stresses, which are due to unequal temperature coeiicients of expansion, are reduced and, in some cases, substantially eliminated.

In the accompanying drawings, Fig. 1 is a cross-sectional elevation` of a hydraulic coupling of the Fttinger type in which the guide vane diaphragm is mounted in the casing, with provision being made for radial expansion in accordance with our invention: Fig. 2 is a plan a cross-sectional elevation ,illustrating a modification of the guide diaphragm structurev of Figs. 1 and 2; Fig. 4 is a plan view of the diaphragm of Fig. 3; Fig. 5 is another modification of the diaphragm structure illustrated in Fig. 1; Fig. 6 is a modification of Fig. r5 and Fig.v '7 is a modifi-f Referring to the drawings in detail, Fig. 1 is a cross-sectional elevation through the center of a Fttingertype coupling. This type coupling is described in detail S. Patents 1,199,359 to 1,199,361, issued to Fttinger. As shown in Fig. 1, this coupling comprises a metal casing made up o1' cast iron or steel shells'll and I2 joined together along their peripheral flanges I3 andy Il. A driving shaft I5 projects 'through a bearing sleeve I6 in theY shell I2 andsupports a pump wheel I1. A driven shaft I8 projects throughy a sleeve I9 in the shell' II 'and supports a turbine wheel 20 within the casing. The pump wheel Il., `is provided with impeller vanes2 I, the outer-endsl of which are held by a shroud 22.` The turbine f wheel is provided with vanes, 23, the'outer ends o f which are held by a shroud 24.v Fluid in the casing is iinpelled by the pump vanes 2| 'against the turbine vanes 23 and is discharged by the latterinto'a return channel formed by the sta- `tionary guide diaphragm' with the casing wall.

This diaphragm comprises'an outer, or shroud, ring 25, an inner, or centraLring 26, and guide vanes 21 connected between these two rings. The

. inner, or central, ring 26 is shaped to' form a chanterialused for the casing elementsII and I2.

elevation of the diaphragm of Fig. 1; F18. 3 is 55 nel having the necessary width for conducting the operating fluid within the casing from the discharge side of the turbine vanes tothe intake side of the `pump vanes, the guide vanes 21 in` this guide channel serving to guide `this fluid in its rotation in relation tothe axis of the wheel. The rings 25 and 26 are made of .alight weight metal such as aluminum, or* an alloy thereof, which has a greater temperature coemcient of expansion than irony or steel which is the ma- .In Fig. 1, the outer guide, or shroud,fring 25 mounted in an annular channe1,. in the casing;

said annular channel having a bottom surface 2l land having parallel side walls 29,30.. -Substanl tially no clearance is provided betweenthe para1y lel side walls of the channel andthe ends of the ring 25, but a substantial clearance is` provided between the outer surface of the ring and the bottom surface 28 in the channel, for radial expansion. The clearance space in this channel exists duringy low temperatures, such as exist at starting, and does not interfere with the operation of the coupling, since there is substantially no leakage between the parallel channel sides and the sides of the diaphragm ring. When the coupling heats up, the larger expansion of the guide diaphragm relatively to the casing, eliminates this clearance space, but no radial pressure is exerted upon, and no strains are set up within, the casing.

Fig. 2 is a plan elevation of the coupling illustrated in Fig. 1 having the shell I2 removed to illustrate the means for mounting the guide vane diaphragm, centrally, Within the casing. For this purpose, four equally. spaced projections or lugs 32 are provided. These lugs project above the channel surface 28 and project into slots 33 in the ring. The slots in the-diaphragm ring are made only slightly wider than the lugs in the channel so that there is a slide lit between the two, but no clearance space. A clearance space is left, however, between the end surface of the lug 32 and the bottom of the slot 33. With this arrangment and spacing of the lugs and slots, the diaphragm is held centrally within the hydraulic casing at all temperatures. Simultaneously, a radial expansion is provided in al1 directions.

In Figs. 3.and 4, a modified guide diaphragm is illustrated. n This guide diaphragm comprises an outer, or shroud, ring 35, guide vanes 38, and an inner, or central, ring 31. The outer, or shroud, ring 35 is provided with three equally spaced slots 38, and the inner ring 31. is provided with three equally spaced slots 39 as shown in Fig. 4..

of the fact'that each segment expands by itself.l

the outer diameter of the ring remains constant. and substantially no radial stresses are applied tothe casing. y l

In Eig. 5, a modified outer ring and a 'modified annular channel are used. An annular channel 'in the casing is provided with a cylindrical bottom surface 4I and with conical sides 42 and 43 which give this channel a cross-section which resembles a frustum of a cone. The end surfaces of the ring 44 are also conical and parallel to the sides of the channel. Furthermore, the width of the ring 44 and, therefore, the spacing of the end surfaces of the ring is such that the ringdoes not fill the channel and a clearance space is left between the circumference of the ring 44 and the bottomsurface 4| of the channel at starting temperature's. During operation, the ring expands at a greater rate than they casing, and is, therefore, forced deeper into the wedge-shaped channel. The radial forces exerted by this expansion are relatively small in view of the fact that the pressure is actually exerted upon the conical sides and is to-a great proportion in a horizontal direction. In view of the fact thatl the diaphragm` is in contact with these conical sides, at all temperatures, it is centrally supported throughout the operating temperature range, and no special means are needed for centrally supporting the diaphragm. l

Fig. 6 discloses a modification of the outer ring 44 of the guide vane diaphragm illustrated in Fig.

5. In this modification the ring is provided with' slots 45 and 46 extending inwardly from the sides of the ring. The slots 45 and 46 are similar to the slots 33 in the ring 35. They do not split the ring completely but extend inwardly from the sides of the ring up to the sides of the guide vanes and are spaced from each other in any desired manner. An equal spacing is preferable, and the number of slots used is dependent upon the resiliency and size of the diaphragm. In the illustrated coupling three equally spaced slots are used on each side of the ring. During operation, the ring expands and as it moves into the narrower part of the channel the ends of the ring contract, thereby still further reducing the radial pressure against the channel sides.

Fig. 7 illustrates a modication of Fig. 2. In this modification three equally spaced lugs 41 are provided in the periphery of the guide vane diaphragm ring 43. Three slots 43 are correspondingly provided in the bottom surface li. of

the channels in which ring 43 is mounted. In this modication, a clearance space is left between the end surface of the' lug and the bottom of the supporting slot and a slide fit is provided between the sides of the. lug and slot. In this manner, the diaphragm ring is supported at three equidistant points, and therefore, remains centrally within thecasing at all temperatures. A clearance space is left at all points of the circumference so that a radial expansion is possible within the casina without the application of radial stresses against the casing.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In a hydraulic power transmitting device, the combination of a metal casing, a guide-vane diaphragm made of a metal'having a higher cceilicient of expansion than the metal of said casing, and means providing radial resiliency in .said diaphragm to compensate for this dierence segments, the dividing points on said central n ring and said shroud ring being intermediate each Other. .5o g

3. In a hydraulic coupling the combination of a casing, a pump wheel and a turbo wheel therein and a guidediaphragm. said diaphragm comprising an inner ring divided into segments, guide vanesV attached to said segments. and a shroud ring attached to the outer .end of said guide vanes,

said shroud ring being divided into segments at points circumferentially intermediate the points of division betweensaid inner. ring segments.

4. A diaphragm for a hydraulic coupling comprisingka central ring divided into segments, said segments being spaced from each other by gaps lwhich are substantially closedat normal operating temperatures, guide. vanes attached to the periphery of said central ring, and a shroud ring attached to the outer end of said -guide vanes, said shroud ring being divided into segments at points intermediate the dividing points -on said central ring, said shroud ring segments being spacedl` from each other by gaps which are substantially ltclosed at Vnormal operating temperatures.

WILLY BLACK. RUDOLF FICHTNER. 

